Autonomous Decentralized System for Service Assurance and Its Application -- Autonomous Decentralized System for Service Assurance and Its Application -- Middleware -- A Message Oriented Middleware Solution Enabling Non-repudiation Evidence Generation for Reliable Web Services -- Comparing Robustness of AIS-Based Middleware Implementations -- Service-Oriented Operating System: A Key Element in Improving Service Availability -- Software Systems -- Implementation of Highly Available Memory Database as SAF Component -- Fault Tolerant Schemes for Hot-Swappable and Non Hot-Swappable Mezzanine Cards -- Experience in Developing a High Availability and Continuous TCP Using OpenAIS and TCPCP -- Modeling and Analysis -- Client-Centric Performance Analysis of a High-Availability Cluster -- A Faster Estimation Algorithm for Periodic Preventive Rejuvenation Schedule Maximizing System Availability -- Model-Driven Development and Human Engineering -- An Eclipse-Based Framework for AIS Service Configurations -- MDDPro: Model-Driven Dependability Provisioning in Enterprise Distributed Real-Time and Embedded Systems -- Applying US DoD Human Engineering Methods to Reduce Procedural Error Related Outages.

Program Chairs' Message th The 4 International Service Availability Symposium (ISAS 2007) continued with the tradition of its predecessors by bringing together researchers and practitioners from both academia and industry to address the problems of service availability. The unique characteristic of a strong academic and industrial partnership was vividly - flected in this year's event, from the Organizing Committee to the contributions and the participants. Recognizing the value of broadening the scope of ISAS 2007, we included new topic areas that cover model-driven design and human factors. We received a total of 25 submissions, each of which was thoroughly reviewed by at least three members of the Program Committee. Due to the limited time allocated for the symposium, many worthwhile manuscripts unfortunately did not make it into the final program. Our sincere thanks go to the Program Committee for conducting a vigorous review process in a rather tight time schedule. The detailed reviews and their generous comments have shaped the contributions into an excellent program.